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Abstract:

An apparatus for monitoring eye movement in a patient, includes a frame
structured to be worn on the head of the patient. An infrared
illumination device structured to illuminate an eye of the patient is
supported by the frame. A camera structured to capture images of the eye
when illuminated by the infrared illumination device is also supported by
the frame. A number of sensors structured to generate data relating to
one or more characteristics of the user or environment is further
supported by the frame. The apparatus also includes a data storage device
associated with the frame for recording the images and the data relating
to one or more characteristics of the user or environment along with time
information associated therewith. The apparatus is structured to
generally not obstruct the patient's view of their surroundings.

Claims:

1. An apparatus for monitoring eye movement in a patient, the apparatus
comprising: a frame structured to be worn on the head of the patient; an
infrared illumination device supported by the frame, the infrared
illumination device structured to illuminate an eye of the patient; a
camera supported by the frame, the camera structured to capture images of
the eye when illuminated by the infrared illumination device; a number of
sensors supported by the frame, the number of sensors structured to
generate data relating to one or more characteristics of the user or
environment; and a data storage device associated with the frame for
recording the images and the data relating to one or more characteristics
of the user or environment along with time information associated
therewith, wherein the apparatus is structured to generally not obstruct
the patient's view of their surroundings.

2. The apparatus according to claim 1, wherein the number of sensors
comprises a motion sensor, the motion sensor being structured to generate
data relating to a position of the head.

3. The apparatus according to claim 1, wherein the number of sensors
comprises a luminance sensor for measuring data relating to ambient
luminance.

4. The apparatus according to claim 1, wherein the number of sensors
comprise: a motion sensor, the motion sensor being structured to generate
data relating to a position of the head; and a luminance sensor, the
luminance sensor being structured to measure data relating to ambient
luminance.

5. The apparatus according to claim 1, wherein the camera is adapted to
capture the images at a frame rate of at least 60 Hz.

6. The apparatus according to claim 1, wherein the frame comprises a main
portion and a pair of side portions, wherein the main portion comprises a
reflective member supported thereon, and wherein the camera is supported
by one of the side portions and structured to capture images of the eye
reflected by the reflective member.

7. The apparatus according to claim 1, wherein the data storage device is
supported by the frame.

8. The apparatus according to claim 1, wherein the frame comprises a
transmitter supported thereon; wherein the data storage device is
separated a distance from the frame; and wherein the transmitter is
adapted to transmit, and the data storage device is adapted to receive
and record, the images and the data relating to one or more
characteristics of the user or environment along with time information
associated therewith.

9. The apparatus according to claim 1, wherein the frame comprises
another camera supported thereon, the another camera being structured to
capture images of the patient's surroundings.

10. An apparatus for monitoring eye movement in a patient, the apparatus
comprising: a frame structured to be worn on the head of the patient; an
infrared illumination device supported by the frame, the infrared
illumination device structured to illuminate an eye of the patient; a
camera supported by the frame, the camera structured to capture images of
the eye when illuminated by the infrared illumination device; a luminance
sensor supported by the frame, the luminance sensor structured to
generate data relating to the measured ambient luminance; and a data
storage device associated with the frame for recording the images and
data relating to one or more characteristics of the user or environment
along with time information associated therewith.

11. A method of diagnosing episodic occurrences of dizziness or vertigo
in a patient using the apparatus of claim 1, the method comprising:
providing the apparatus to the patient; receiving data recorded by the
patient using the apparatus; and analyzing the data for the purpose of
diagnosing a particular disorder or condition.

12. The method according to claim 11, wherein the data recorded comprises
images of the eye and data describing ambient luminance at the time the
images of the eye were recorded, and wherein analyzing the data comprises
analyzing both the images of the eye and the data describing the ambient
luminance.

13. The method according to claim 11, further comprising: instructing the
patient to don the apparatus when symptoms of at least one of dizziness
and vertigo are experienced; and instructing the patient to perform at
least one of a number of activities once the apparatus is donned by the
patient.

14. The method according to claim 13, wherein the number of activities
comprise: sitting upright in a lighted room; sitting upright in a
darkened room; looking right, left, up, and down; lying supine in a dimly
lit environment; and lying on the right and left side in a dimly lit
environment.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority under 35 U.S.C. §119(e) from
U.S. Provisional Application No. 61/221,735, entitled "Goggles for
At-Home Eye Movement Monitoring", which was filed on Jun. 30, 2009, the
disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to changes in the eye, and more
particularly, to an apparatus and method for monitoring and recording
changes in the eyes of a patient.

BACKGROUND OF THE INVENTION

[0003] The presence of a number of medical and health problems can be
detected by changes in the eye, including unusual changes in the
position, movement and dilation of the eye. For example, it has been
found that one of the leading causes of dizziness and balance problems is
associated with the vestibular system in the inner ear. The presence of
nystagmus (very specific, rapid, involuntary eye movements) during a
dizziness attack can suggest to a clinician that there is a vertiginous
component to it and the direction of the nystagmus may provide some
evidence to a specialist in the field, of more specific information, such
as which ear (or which part of the ear) has the active disease.

[0004] Dizziness and balance problems constitute a major public health
problem. A significant proportion of adults have had an episode of
dizziness that occurs with enough intensity or frequency to promote a
visit to a physician. It is one of the most difficult complaints for a
physician to assess, as dizziness is generally a subjective symptom of
potentially numerous causes. Additionally, dizziness is often an episodic
symptom, with the frequency of episodes highly variable. As a patient
will very rarely have an episode while actually in the clinic, clinicians
are frequently forced to rely solely on the patient's (often
unintentionally misleading) report of the symptom(s).

[0005] Accordingly, accurate diagnosis of balance symptoms is important
not only to exclude potentially serious central nervous system causes but
to aid successful treatment. Unfortunately diagnosis is sometimes not
possible, or is delayed. Studies have shown that general practitioners
(GPs) rarely failed to refer urgent cases to specialists but often failed
to refer patients with persistent vestibular conditions. Part of the
difficulty is that the known apparatus for detecting and recording
nystagmus and other eyes movements are large, expensive machines that are
only available for use by specialists. Due to the size, complexity and
expense of such machines, they are typically limited to laboratory use
for specific tests. Such machines are rarely used to monitor patients at
the time of a dizziness episode.

[0006] The present invention was developed with a view to providing a
portable device for the investigation of eye movements that may occur
during episodic vertigo and dizziness and a method of conducting the
investigation using the device. The device can be used away from the
clinic and does not need a specialist to operate it. However it will be
understood that the device may also be used more generally in oculography
and for investigation of the eye.

[0007] References to prior art in this specification are provided for
illustrative purposes only and are not to be taken as an admission that
such prior art is part of the common general knowledge.

SUMMARY OF THE INVENTION

[0008] In one non-limiting embodiment, the invention provides an apparatus
for monitoring eye movement in a patient. The apparatus comprises: a
frame structured to be worn on the head of the patient; an infrared
illumination device supported by the frame, the infrared illumination
device structured to illuminate an eye of the patient; a camera supported
by the frame, the camera structured to capture images of the eye when
illuminated by the infrared illumination device; a number of sensors
supported by the frame, the number of sensors structured to generate data
relating to one or more characteristics of the user or environment; and a
data storage device associated with the frame for recording the images
and the data relating to one or more characteristics of the user or
environment along with time information associated therewith, wherein the
apparatus is structured to generally not obstruct the patient's view of
their surroundings.

[0009] The number of sensors may comprise a motion sensor, the motion
sensor being structured to generate data relating to a position of the
head. The number of sensors may comprise a luminance sensor for measuring
data relating to ambient luminance. The number of sensors may comprise a
motion sensor and a luminance sensor, the motion sensor being structured
to generate data relating to a position of the head and the luminance
sensor being structured to measure data relating to ambient luminance.

[0010] The camera may be adapted to capture the images at a frame rate of
at least 60 Hz.

[0011] The frame may comprise a main portion and a pair of side portions,
wherein the main portion comprises a reflective member supported thereon
and wherein the camera is supported by one of the side portions and
structured to capture images of the eye reflected by the reflective
member.

[0012] The data storage device may be supported by the frame. The frame
may comprise a transmitter supported thereon, the data storage device may
be separated a distance from the frame, and the transmitter may be
adapted to transmit the images and the data relating to one or more
characteristics of the user or environment along with time information
associated therewith to the data storage device for recording thereon.

[0013] The frame may comprise another camera supported thereon, the
another camera being structured to capture images of the patient's
surroundings.

[0014] In another non-limiting embodiment, the invention provides an
apparatus for monitoring eye movement in a patient. The apparatus
comprises: a frame structured to be worn on the head of the patient; an
infrared illumination device supported by the frame, the infrared
illumination device structured to illuminate an eye of the patient; a
camera supported by the frame, the camera structured to capture images of
the eye when illuminated by the infrared illumination device; a luminance
sensor supported by the frame, the luminance sensor structured to
generate data relating to the measured ambient luminance; and a data
storage device associated with the frame for recording the images and the
data relating to one or more characteristics of the user or environment
along with time information associated therewith.

[0015] In a further non-limiting embodiment, the invention provides a
method of diagnosing episodic occurrences of dizziness or vertigo in a
patient using an apparatus. The apparatus comprises: a frame structured
to be worn on the head of the patient; an infrared illumination device
supported by the frame, the infrared illumination device structured to
illuminate an eye of the patient; a camera supported by the frame, the
camera structured to capture images of the eye when illuminated by the
infrared illumination device; a number of sensors supported by the frame,
the number of sensors structured to generate data relating to one or more
characteristics of the user or environment; and a data storage device
associated with the frame for recording the images and the data relating
to one or more characteristics of the user or environment along with time
information associated therewith, wherein the apparatus is structured to
generally not obstruct the patient's view of their surroundings. The
method comprises: providing the apparatus to the patient; receiving data
recorded by the patient using the apparatus; and analyzing the data for
the purpose of diagnosing a particular disorder or condition.

[0016] The data recorded may comprise images of the eye and data
describing ambient luminance at the time the images of the eye were
recorded, and analyzing the data may comprise analyzing both the images
of the eye and the data describing the ambient luminance.

[0017] The method may further comprise: instructing the patient to don the
apparatus when symptoms of at least one of dizziness and vertigo are
experienced; and instructing the patient to perform at least one of a
number of activities once the apparatus is donned by the patient. The
number of activities may comprise: sitting upright in a lighted room;
sitting upright in a darkened room; looking right, left, up, and down;
lying supine in a dimly lit environment; and lying on a right and left
side in a dimly lit environment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings illustrate presently preferred
embodiments of the invention, and together with the general description
given above and the detailed description given below, serve to explain
the principles of the invention. As shown throughout the drawings, like
reference numerals designate like or corresponding parts.

[0019] FIG. 1 is an isometric view of the front of an apparatus for
monitoring eye movement in a patient according to an embodiment of the
present invention;

[0020] FIG. 2 is an elevation view of the rear of the apparatus of FIG. 1;

[0021] FIG. 3 is a plan view of the top of the apparatus of FIG. 1
positioned on the head of a patient;

[0022] FIG. 4 is a top view of a portion of an apparatus for monitoring
eye movement in a patient according to another embodiment of the present
invention; and

[0023] FIG. 5 is an elevation view of the rear of the portion of the
apparatus shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Directional phrases used herein, such as, for example and without
limitation, top, bottom, left, right, upper, lower, front, back, and
derivatives thereof, relate to the orientation of the elements shown in
the drawings and are not limiting upon the claims unless expressly
recited therein.

[0025] As employed, herein, the statement that two or more parts or
components are "coupled" together shall mean that the parts are joined or
operate together either directly or through one or more intermediate
parts or components.

[0026] As employed herein, the statement that a part or component
"supports" another part or component shall mean that the second part or
component may be coupled to, or otherwise generally mounted to, the first
part or component.

[0027] As employed herein, the term "number" shall mean one or an integer
greater than one (i.e., a plurality).

[0028] FIGS. 1-3 show an apparatus 10 for monitoring eye movements in a
patient according to an embodiment of the present invention. Apparatus 10
includes a frame assembly 12 that is adapted to be worn on the head 8 of
a patient, such as depicted in the top view of FIG. 3. Preferably, frame
assembly 12 is a lightweight, yet robust member formed from metal,
plastic, or other suitable material. Although shown as essentially an
eyeglass frame in FIGS. 1-3, it is to be appreciated that frame assembly
12 may comprise other suitable structures that may be readily fitted on
or to the head of a patient at or about the patient's eyes.

[0029] Frame assembly 12 includes a main portion 14 and a pair of side
portions 16. Main portion 14 is structured to generally be disposed in
front of the eyes of a patient and rest on the patient's nose. Side
portions 16 are structured to extend generally along either side of the
patient's head and may slightly engage the patient's ears in order to
help secure apparatus 10 to the patient's head. Side portions 16 may be
integrally formed with main portion 14 or formed separately and either
fixedly or pivotably coupled to main portion 14. Although not shown in
FIGS. 1-3, apparatus 10 may further include a strap or other suitable
mechanism to assist in securing apparatus 10 to a patient's head,
preferably in a comfortable manner. As will be discussed further below,
frame assembly 12 is adapted to support a number of monitoring components
while generally not obstructing a patient's vision of their general
surroundings. Accordingly, it is preferred that a patient may wear the
apparatus 10 with similar comfort as a pair of reading glasses or
sunglasses and be able to do basic activities (discussed further below)
without being impeded by the apparatus 10.

[0030] FIG. 2 shows a rear view (the side which faces the patient) of the
apparatus 10 that shows a number of the monitoring and related components
supported by the frame assembly 12. Such components include a number of
infrared light sources 18 supported on the frame assembly 12 for
illuminating each of the eyes 9 of the patient. The embodiment shown in
FIG. 2 includes four infrared light sources 18, two for each eye, coupled
generally to a lower portion (not numbered) of main portion 14. The
infrared light sources 18 may be light emitting diodes (LEDs) or other
suitable infrared light sources supported on, or generally in, the frame
assembly 12 and may include one or several for each eye. Continuing to
refer to FIG. 2, a pair of cameras 20 are supported on the frame assembly
12, each camera being positioned to capture images of one of the
patient's eyes when illuminated by the infrared light sources 18. Such
cameras 20 may comprise any suitable imaging device capable of focusing
and recording images of the patient's eyes. Important factors to be
considered in choosing a suitable camera are focal length, sensor sizes,
distance to image plane, image size and aperture (light). One particular
preferable requirement of the lens mechanism (not numbered) of a camera
20 is to have a depth of field that will allow the eye image to be always
in focus. As different users will have varying length between the lens
and eye, the lens will usefully have a depth of field over this range.
Another possibility is to employ a camera 20 employing auto-focusing
technology or other focusing mechanism that may be adjusted by the
patient and/or a clinician during an initial fitting.

[0031] In the example embodiment shown, each camera 20 employs a digital
image sensor, currently CMOS or CCD technologies are suitable. Each image
sensor typically includes a CCD sensor and controller and preferably
include a lens incorporated into or attached thereto. The image sensors
are operated to capture images at a predefined frame rate, preferably at
least 60 Hz. The images of the patient's eye 9 captured by camera 20 may
be processed to correct the images for such photographic problems as
over-exposure or under-exposure, bad pixels, etc, prior to being stored
on storage/recording device 22, which is in communication with each of
the cameras 20. Storage/recording device 22 may be of any suitable
storage means capable of storing a quantity of digital images and other
electronic information and preferably has a storage capacity that can
accommodate at least one hour of recorded images and other data in a
format that can be easily transferred to a desktop computer.
Storage/recording device may be supported on, and/or integrated with, the
frame assembly 12. In such arrangement, storage/recording device 22 is
preferably electrically coupled to each of the cameras 20 via wiring.
Although not shown in the FIGS., it is to be appreciated that
storage/recording device 22 may also be separate from the frame assembly
12. In such application, a suitable transmitter is further provided on
the frame assembly 12 for wirelessly transmitting image and other signals
from the frame assembly to the storage/recording device 22.

[0032] Referring to FIGS. 2 and 3, the apparatus 10 preferably includes a
number of sensors 24 supported by frame assembly 12 and in communication
with recording device 22 for generating and storing data relating to one
or more characteristics of the user and/or the environment. For example,
a motion sensor may be provided on frame assembly 12 for detecting the
relative position of the patient's head and generating data regarding
such positioning. Such data are recorded on recording device 22. As
another example, a luminance sensor may also be provided for measuring
data related to ambient luminance. Such characteristics of the user and
environment are important to record as they may have a causal
relationship on the symptoms experienced by the patient or the patient's
eye movements. As a further example, a third camera may be provided to
capture images of the patient's surroundings.

[0033] FIGS. 4 and 5 show top and rear views of a portion of an apparatus
10' for monitoring eye movements in a patient according to another
embodiment of the present invention. Like apparatus 10 previously
discussed, apparatus 10' includes a frame assembly 12 having a main
portion 14 and a pair of side portions 16. However, unlike the previously
discussed apparatus 10, which utilized cameras 20 aimed directly at each
of the patient's eyes, the apparatus 10' of FIGS. 4 and 5 utilizes a
camera 20 for each eye that is generally supported on the side portion 16
and relies on a reflective member 26, such as a small mirror, to reflect
images of the eye which are captured by camera 20', and subsequently
transmitted to a recording device 22, as discussed in connection with the
embodiment shown in FIGS. 1-3. Such arrangement allows for the use of a
generally larger camera 20' or for a camera 20' having a relatively
longer focal distance.

[0034] As such it is to be appreciated that the present invention provides
a relatively compact apparatus that may be worn by a patient during many
normal daily activities or that may be readily donned by a patient when
symptoms of dizziness or vertigo are first sensed. Accordingly, it is
envisioned that the apparatus would be "loaned" to a patient on a
temporary basis by a prescribing physician. The apparatus thus would
allow a patient to record their eye movements during episodes of
dizziness and vertigo, wherever such episodes may occur. Eye position is
then computed off-line, prior to analysis by an expert physician. Other
potential causal elements, such as time of day, ambient luminance, and
head position are also recorded and correlated with the images of the
eyes for analysis by the expert physician. Such recorded data will then
enable physicians to evaluate physiologic data collected during attacks
of dizziness and vertigo and thereby improve the diagnostic accuracy, and
thus treatment of many common balance disorders.

[0035] In a preferred use of the apparatus 10, a patient dons the
apparatus 10 when they first feel the symptoms of dizziness or vertigo.
Once donned, the patient then performs several simple maneuvers such as:
sitting upright in a lighted room; sitting upright in a darkened room;
looking right, left, up, and down; lying supine in a dimly lit
environment; and lying on their right and left side in a dimly lit
environment. The images of the eye are then processed using image
analysis software to generate a record of horizontal, vertical and
torsional eye position versus time with an accompanying record of time of
day, ambient luminance, and head position with respect to gravity. Such
data is then analyzed by an ordering physician along with the video
images of the eye movements and incorporated into the diagnostic process.

[0036] While preferred embodiments of the invention have been described
and illustrated above, it should be understood that these are exemplary
of the invention and are not to be considered as limiting. Additions,
deletions, substitutions, and other modifications can be made without
departing from the spirit or scope of the present invention. Accordingly,
the invention is not to be considered as limited by the foregoing
description but is only limited by the scope of the appended claims.

Patent applications by University of Pittsburgh - Of the Commonwealth System of Higher Education